The present invention relates to a cassette loading mechanism for use in magnetic recording and/or reproducing apparatus such as a video tape recorder. Specifically, the present invention is suitably applied to a so-called front loading type cassette loading mechanism in which a cassette holder adapted to hold a tape cassette is moved vertically and horizontally by utilizing the driving force of a motor, that is, the cassette holder (tape cassette) is first moved in a horizontal direction and then moved in a vertical direction.
An example of this front loading type cassette loading mechanism (hereinafter referred to as "front loading mechanism") is constituted in the manner illustrated in FIGS. 1 to 4.
FIG. 1 shows a schematic plan view of a conventional front loading mechanism; FIG. 2 shows a side view of this eechanism seen from the left hand side; FIG. 3 shows an exploded perspective view of an essential part of this mechanism; and FIG. 4 shows a cross-sectional view of this essential part. As shown in these drawings, the front loading mechanism has a cassette holder 2 mounted between a left side bracket 3a and a right side bracket 3b. This cassette holder 2 is supported by means of shafts lla, llb, 12a and 12b, and rollers 14a, 14b, 15a and 15b such as to be movable along L-shaped guide slits G.sub.1, G.sub.1 and G.sub.3, G.sub.3 formed in the left and right side brackets 3a and 3b which are fixed to a main chassis 3 and acts as a member for positioning the entire part of the cassette loading mechanism. The shafts 11a, 11b, 12a and 12b are embedded in both side walls of the holder 2. Rollers 14a, 14b, 15a and 15b are fitted to the shafts lla, llb, 12a and 12b, and parts of these rollers are engaged with the guide slits G.sub.1 and G.sub.2 of the brackets 3a and 3b. Drive arm 22a and 22b and drive gears 21a and 21b are attached to a synchronizing shaft 25, and these arms have elongated holes H into which the rollers 14a and 14b are inserted. The drive gears 21 a and 21b are adapted to be rotated by the driving force of a motor (not shown). The synchronizing shaft 25 is rotatably mounted on the left and right side brackets 3a and 3b.
The operation of this mechanism will be described below. When a cassette 1 is inserted into and positioned in the cassette holder 2, a detection switch (not shown) is switched on by the operation of the cassette holder 2, thereby driving the motor. The driving force of the motor is transmitted to, e.g., the gear 21a via a speed reduction mechanism constituted by, e.g., a worm gear. When the gear 21a is rotated anticlockwisely, the drive arm 22a is also rotated in the same direction while turning the gear 21b and the driving arm 22b, and the arm 22a applies a force to the cassette holder 2 in the leftward direction, so that the holder 2 is transported in the horizontal direction toward the inner part of the apparatus while carrying the cassette 1 and being guided along the guide slits G.sub.1, G.sub.2. After being moved a predetermined distance, the cassette holder 2 is guided along vertical portions of the guide slits G.sub.1 and G.sub.2 so as to be transported vertically and downwardly.
After the cassette 1 is loaded in a given position, a magnetic tape (not shown) incorporated in the cassette 1 is extracted by a tape loading mechanism (not shown) of the video tape recorder to be wound around a cylinder (not shown) having recording and reproducing heads, thereby effecting recording on the magnetic tape and reproduction of the same.
As described above, in the conventional cassette loading mechaiism, rotary members for driving the holder 2, namely, the drive arms 22a and 22b are positioned outside the brackets 3a and 3b so that the size of the mechanism is necessarily large, thus conflicting with the design requirements for reducing the size, height, and weight of the magnetic recording and/or reproducing apparatus.